Field of the Invention
The present invention relates to a technology for detecting a subject image from an image and controlling zoom magnification.
Description of the Related Art
In the related art, there are imaging apparatuses that have a function of driving a zoom lens and performing optical magnification (hereinafter referred to as optical zoom) and a function of expanding a part of a photographed image and performing electronic magnification (hereinafter referred to as electronic zoom). The imaging apparatuses also have an automatic zoom function (automatic magnification) of automatically changing a zoom magnification according to detection information of subjects. Hereinafter, an optical zoom operation and an electronic zoom operation are collectively referred to as a zoom operation.
Japanese Patent Laid-Open No. 2012-95019 discloses the configuration of a camera equipped with an automatic zoom function of constantly maintaining the size of a subject. Japanese Patent Laid-Open No. 2012-95019 discloses a method in which a photographer selects a composition among a plurality of options, “face-up,” “bust-up,” and “whole body,” in an automatic zoom function. In automatic zoom control of maintaining the size of a subject image, the size of the subject image serving as a basis of zoom control is decided based on a selected composition. For example, when a photographer selects the composition “whole body,” a zoom operation is performed so that an image of the whole body of a person that is a subject fits in a photographing screen.
In Japanese Patent Laid-Open No. 2012-95019, however, it is necessary to select a composition desired by a photographer in advance in an automatic zoom function. Therefore, whenever a photographing scene or a subject state (a motion, a number, or the like) is changed, it is necessary for the photographer to perform a setting changing manipulation. When setting of the composition is not appropriate for a photographing scene, there is a possibility of a subject not being imaged with an appropriate size. For example, when a composition of “face” is set in a scene in which a moving subject or a distant subject is photographed, there is a possibility of a subject falling outside of a frame. When a composition of “whole body” is set in a scene in which a stopped subject is photographed, there is a possibility of a subject being considerably small in a composition.
When a specific subject is desired to be photographed with the same composition, it is necessary to perform a setting changing manipulation again whenever a subject is changed. For example, when a baby is desired to be photographed with a close-up on his or her “face” or a child is desired to be photographed with the composition of “whole body,” the photographer has to manually change setting of the composition when a subject changes.